Dynamics of charge-imbalance-resolved entanglement negativity after a quench in a free-fermion model

The presence of a global internal symmetry in a quantum many-body system is reflected in the fact that the entanglement between its subparts is endowed with an internal structure, namely it can be decomposed as a sum of contributions associated to each symmetry sector. The symmetry resolution of entanglement measures provides a formidable tool to probe the out-of-equilibrium dynamics of quantum systems. Here, we study the time evolution of charge-imbalance-resolved negativity after a global quench in the context of free-fermion systems, complementing former works for the symmetry-resolved entanglement entropy. We find that the charge-imbalance-resolved logarithmic negativity shows an effective equipartition in the scaling limit of large times and system size, with a perfect equipartition for early and infinite times. We also derive and conjecture a formula for the dynamics of the charged Renyi logarithmic negativities. We argue that our results can be understood in the framework of the quasiparticle picture for the entanglement dynamics, and provide a conjecture that we expect to be valid for generic integrable models.

Automated summary

The discussion focuses on the impact of global internal symmetry on entanglement properties in quantum many-body systems, and examines the non-equilibrium state of the system through the study of dynamics of charge-imbalance entanglement and charged Renyi logarithmic negativities. The research findings suggest that under specific conditions, the entanglement exhibits equipartition behavior.